


Sinful Perfection

by HikariNoHimeWriter



Category: Dr. STONE (Anime), Dr. STONE (Manga)
Genre: Dubious Consent, Established/Past Relationship, Hurt and Smut, Incest, M/M, Mentions of Hyouga/Ishigami Senkuu - Freeform, Possessiveness, SpringFicletExchangeTKS2020, TKSevents, TheKingdomofShipping, This author is too anxious to wait for beta, age gap
Language: English
Status: Completed
Published: 2020-04-01
Updated: 2020-04-01
Packaged: 2021-02-28 22:55:49
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,140
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23435023
Author URL: https://archiveofourown.org/users/HikariNoHimeWriter/pseuds/HikariNoHimeWriter
Summary: Byakuya loves his Senku. Now all he needs to do is remind his son that he, too, loves Byakuya.
Relationships: Ishigami Byakuya/Ishigami Senkuu
Comments: 2
Kudos: 44
Collections: 2020 TKS Spring Ficlet Gift Exchange





	Sinful Perfection

**Author's Note:**

  * For [Animillion](https://archiveofourown.org/users/Animillion/gifts).



> This is a gift to my dearest Ani! Guess my surprise when I got you this time XD  
> I tried to get some of the things you wanted and mix them together but, uh, even if I got way past the limit it's still too little XD  
> Hope you like your gift uwu

_Senku looks happy_ , is the first thing Byakuya notices when he sees his son walking the small steps to his apartment building. Somehow he can’t help the excitement coursing through his veins. Is his boy happy to come back home, to see Byakuya again after all those months? Did he think, dream of this day like Byakuya did?

He snorts, leaning heavily against the windowsill. Of course not. Senku’s not the type to have sappy thoughts, much less express them freely. If things continued on like this, Byakuya is sure Senku won’t ever find a proper boyfriend. Not that he minds it. Byakuya is nothing but pleased at the thought of keeping Senku and all the wonderful memories to himself only.

Which is why his face turns into a deep frown when, barely a second later, a man with snow white hair walks after Senku. Byakuya can’t see his face at the distance—he does live at the third floor, after all—but he can tell this man is talking to Senku. Senku, who doesn’t ignore or walk away as he usually does with strangers. Senku, who turns to look at the man only to be pulled into a kiss.

_A kiss Senku returns._

Byakuya bites his lip, unsure of what he’s feeling right now. Anger? Jealousy? Betrayal? _Fear_? A mix of all of them? He doesn’t know. He’s not sure he wants to know either.

He leaves his spot near the window. Walking back into the kitchen, Byakuya sees everything he prepared for the occasion. He cooked everything he knows Senku likes, bought their favorite wine and even baked a cake. All of this, to make his son feel welcomed and loved in the home Byakuya still thinks of as _theirs_.

He takes in a deep breath, controlling his emotions to the best of his ability. So what if Senku was kissing someone else? It’s been months—exactly eight months and seventeen days—since they last saw each other before Senku left for his research in Africa. Eight months in a foreign country surely would make Senku feel lost and lonely. And the guy had white hair too—Byakuya’s sure it’s a sign, some kind of projection of Byakuya’s image. Yeah, it can only be that, _it has to be_.

The front door opens sooner than Byakuya expected. He practically runs to the living room, wanting to see Senku better, closer, as it should always be. There’s a baggage in his son’s hands, one Byakuya is sure he wasn’t carrying before. _Oh_ , he thinks, _so that’s why that man came_. The thought of the stranger carrying Senku’s baggage around makes Byakuya’s blood boil. He bites his lip, however, knowing it isn’t important now.

All that matters is the boy-turned-adult looking at him from the other side of the room. Senku’s eyes will always be the prettiest Byakuya’s ever seen. Right now they look considering, going up and down Byakuya’s body. Observing, checking, deciding.

A rush of warmth courses through Byakuya’s body. That’s it. That’s the expression he wanted to see, the absolute desire that makes Senku’s usually relaxed posture tense up like a bow string ready to snap.

Byakuya’s not sure when he got so close to Senku. All he can think of is all the wys he can use to make that string snap and get them back to what they were before Senku left. He wants to hear his son moaning his name, see him gasping for hair as Byakuya pulls his hair, feel his trimmed nails digging into Byakuya’s back. Senku’s cheek feels soft and warm and familiar under Byakuya’s rough fingers. Just a little more. He just needs to lean down a little more to feel his boy’s lips against his again.

But Senku looks away before he can do it. “Dinner will get cold, old man,” is all he says before distancing himself from Byakuya.

Senku’s not looking at him to see the pain in his eyes, not close enough to hear Byakuya’s fingers cracking when he closes his hand into a fist. He gulps, forcing out a smile, before joining his son at the kitchen. Senku doesn’t blink an eye at the carefully arranged table, nor at the fact that dinner tonight is nothing but a collection of all the things he enjoyed eating growing up.

He doesn’t look at Byakuya even as the man starts asking how he’s been doing, the things he did in those past months. “Nothing out of ordinary, London would’ve been funnier.” Byakuya can’t help but flinch at the short, crude answer. He asks no more, trying to enjoy the food as much as he can.

 _He can’t_. It tastes horrible to him, not because the food is bad, but because this reunion isn’t what he wanted, because he has _Senku_ back but not _his boy_. He hates it. But he hates not having Senku, whatever way he can have him, even more.

It’s unfair.

Byakuya stays alone in the kitchen long after they finish the dinner. Even the wine doesn’t taste good, too sour and bitter for his liking. Or maybe he’s the one projecting now. Byakuya is nothing if sour and bitter right now.

He can hear Senku’s shower turning on. Byakuya closes his eyes, contemplating that stupid, stupid idea that doesn’t seem to leave his mind since Senku walked in and did nothing but ignore Byakuya’s advances. His stupid part wins. Byakuya stands up, heading straight into Senku’s bedroom. The door to the joint bathroom is only half-closed, some of the shower’s steam seeping into the room with its suffocating warmth.

Senku’s clothes are already organized in the wardrobe, the familiar collor scheme making Byakuya’s heart twist in longing. He shakes his head, focusing on what he came to get. Senku’s phone lying on the nightstand. The screen is turned downwards, allowing Byakuya to see the E=mc² written in bold red letter across the white case.

He gave it to Senku just a year ago. Byakuya is happy to see that Senku kept it with him. That happiness vanishes quickly when he picks the phone and unlocks it. The home screen is a photo of Senku, smiling against the sunset’s light, a white haired man hugging him from behind with a smile of his own. Byakuya bites his lower lip, finally being able to see the face of the man who kissed his son right before his doorstep.

Byakuya can’t stop himself. He opens Senku’s gallery, going through dozens, hundreds of pictures of and with that man. He finds messages, too. Thousands of them, all sent to _Hyou_ , from joking threats to love confessions.

His hand shakes with all the feelings swirling in his heart. Byakuya forces himself to look away from the phone when he hears the shower turning off. At the same time the phone starts vibrating in his hand with an incoming call. When he looks down at the caller ID, he sees the now familiar _Hyou_ and almost hits the ignore button. He pauses at the last second, another idea coming to his mind. Byakuya accepts the call, setting the volume to the lowest possible so the words coming from the other side will go unheard before setting it back on the nightstand.

“The hell, old man?!” Senku’s annoyed voice soon fills Byakuya’s ears.

He turns to look at his son, mouth going dry as he takes in Senku’s naked torso and round thighs covered by the loose towel hanging around his waist. “You didn’t be a good boy, Senku.” Byakuya grins almost wolfishly, standing up to bring Senku’s attention to him and as far away from the phone as possible. “Isn’t it just fair that you receive your punishment now?”

The trick works. Senku gapes for a moment, cheeks turning slightly red under Byakuya’s teasing tone. He knows what Senku’s thinking about now. The idea of punishment they share is far more pleasurable than they could really explain.

Senku frowns at last, “You’re drunk. Stops getting ideas.” When he tries to walk past Byakuya again he’s stopped by a larger, way stronger hand. Senku’s eyes shot up to look at Byakuya. They’re not just annoyed. Byakuya can see the lust deep inside them, can see it in the way Senku’s breath quickens yet he makes no move to free himself. When he speaks again, his voice sounds breathless, “Let go.”

There’s only one answer to that. _No, never._ Senku’s body trembles as Byakuya utters those words. It’s all Byakuya needs to pull him closer, Senku’s warm breath hitting Byakuya’s face in that sinfully familiar way he remembers all too clearly, and finally claim those lips he wished for so long.

He wraps one arm around Senku’s waist, his other hands grabbing the back of Senku’s neck to keep him close. It doesn’t stop his protests, the lost fight to get free. It all only makes Byakuya want it more, to take and take until Senku remembers who he belongs to—and make sure the person on the other side of the line will know it too.

A delighted shiver courses through Byakuya’s body as he remembers that they’re not alone. Hyou is listening to them, will listen every moan and sigh he gets from Senku and know what kind of perverted boy Senku truly is, that no one but Byakuya can satisfy his needs.

A pained moan erupts from Senku’s lips when his body hits the mattress. The towel is long since gone, exposing all the soft curves and skin Byakuya will be more than pleased to mark again. He touches him, squeezes Senku’s hips and runs his thumbs along the lines of Senku’s tail bone.

“So beautiful,” he whispers, brushing his lips against Senku’s shoulders. He revels in the way Senku shivers under his touches, biting his lips to stop a moan from coming out. “You like this, don’t you? Naughty boy,” he chuckles under his breath.

“S-Shut up!” But Senku’s voice doesn’t hold half of the venom he wants to inflict. Byakuya can _hear_ the arousal in his voice and, if the way Senku shifts and squirms under him is any indication, he can _feel_ it too. “I’m not that boy anymore!”

“Oh, no, of course not." Byakuya nods in agreement, letting his hand trail up and down his little son’s spine. It doesn’t matter if Senku’s twenty already, “ _You’re just_ ** _my_** _boy_.”

He pulls Senku’s ass cheeks apart, letting himself admire that small, pluckering hole before dragging his tongue over it. Senku can’t stop his moans now, pleased sounds mixed with pleas to _stop_ and _let go_ and _I don’t want it!_ None of those stop Byakuya. Senku wants it. Byakuya knows it, can feel it. He can see the proof of it in Senku’s cum staining the night sky themed sheets, in the way he arches back info Byakuya’s embrace when he finally pushes his cock inside him, making an even bigger mess of cum and lubricant and sweat.

Byakuya has no idea how long they stay like this until Senku finally caves in. Byakuya tenses up whe Senku’s trembling fingers bury into his hair, pulling him into a kiss. This one feels completely different from the first one. Senku’s tongue plays along with his, teeth dig into his lower lip in tease and filthy words make Byakuya’s mind spin.

He refuses to be left behind. He fucks him harder, deeper in response. Senku’s moans are everything Byakuya wants to hear, that pleased, tired smile in the afterglow of orgasm is all he wants to see. He just wants Senku. And Senku is right here for him to make his.

“I love you,” he whispers against his son’s ear, his body still trembling as he comes for what could be the third or fourth time inside Senku. He’s warm and happy and, for once, not _lonely_. “I love you so fucking much.” And if his voice sounds shaker than he intended, Byakuya refuses to acknowledge it and Senku’s far too sleepy to care about pointing it out.

Instead, he just pulls Byakuya closer, clutching to him almost like a koala. Byakuya huffs, shifting so his boy can sleep in a more comfortable position. He places a soft kiss to the crown of Senku’s hair, humming a song until he’s sure Senku’s fallen asleep. Byakuya smiles at Senku, beautiful, pleased Senku, before stretching his hand to reach for his boy’s phone.

A smirk grows on his face when he notices the call is still ongoing. So this is the kind of person Senku is with? A helpless pervert of the worst kind? He huffs. Good riddance, then. His dear son deserves way more than this. He brings the phone close to his lips, his words nothing but a whisper in the quiet room:

“ _He is_ ** _mine_**.”

**Author's Note:**

> Come join our family on [The Kingdom Of Shipping Discord server](https://discord.gg/wxmpcfdGP3) 💖  
> Kissus 💖


End file.
